scholarly journals Seasonal steroid variations in relation to maturity stages in the female Pacific red snapper Lutjanus peru in the Gulf of California, Mexico

2018 ◽  
Vol 31 ◽  
pp. 34
Author(s):  
Silvie Dumas ◽  
Silvia Ramirez Luna ◽  
Pablo Pintos Terán ◽  
Evaristo Mañanos ◽  
Lluis Tort
Keyword(s):  
Gulf Of California ◽  
Gonadosomatic Index ◽  
Gonadal Development ◽  
Reproductive Period ◽  
Red Snapper ◽  
Plasma Testosterone ◽  
La Paz ◽  
The Pacific ◽  
Surrounding Areas ◽  
Fishery Species

Reproductive steroid concentration and gonadal development as well as plasma cortisol were investigated during the reproductive period (April to October) of the Pacific red snapper Lutjanus peru, a commercial and important local fishery species in the surrounding areas of Bahía La Paz, Gulf of California, Mexico. Gonads in April were immature and characterized by the presence of oocytes at the chromatin nucleolar and perinucleolar stages. In the next month, more than 50% of the fish showed gonads in vitellogenesis, characterized by the presence of cortical alveoli and early vitellogenic (V1) oocytes. Late vitellogenic and mature gonads were present in July, August and September. Postovulatory follicles were observed only in gonads collected in August, indicating spawning activity of these individuals. The gonadosomatic index (GSI) increased significantly (p <0.05) from April and May to July, when it reached its maximum value. A significant increase (p <0.05) in plasma testosterone (T) was also observed in July compared to previous months, and plasma estradiol (E2) concentration was significantly higher (p <0.05) in September than in April. Cortisol concentration was significantly higher (p <0.05) in September than in May. Significant differences (p <0.05) between gonadal stages were observed for GSI and E2 but not for T. We conclude that the Pacific red snapper, in the surrounding areas of Bahía de la Paz, showed an asynchronous ovarian growth starting in May when water temperature increased and that was characterized by several spawning events.

Conservation, Ecology, and Management of Catfish: The Second International Symposium

2011 ◽  
Keyword(s):  
Gonadosomatic Index ◽  
Gonadal Development ◽  
Reproductive Hormones ◽  
Wild Fish ◽  
Spawning Season ◽  
Plasma Testosterone ◽  
Anterior Portion ◽  
In Captivity ◽  
17Β Estradiol ◽  
Epaxial Muscles

<em>Abstract</em>.—Captive spawning is a strategy to bolster populations of rare madtoms <em>Noturus</em> spp., but very little is known regarding their reproductive development in captivity. The primary goal of this research was to develop methods to stimulate gonadal maturation of captive madtoms. We used the nonimperiled margined madtom <em>N. insignis</em> as a model species to investigate the effects of photothermal regimes on gonadal development and reproductive hormones. We also evaluated testicular development of madtoms injected with common carp <em>Cyprinus carpio</em> pituitary extract (CPE). Changing photoperiod, but not temperature, was required to induce oocyte maturation in a high percentage of captive female margined madtoms. Gonadosomatic index (GSI) values of captive females were similar to those of gravid wild fish collected during or just prior to the spawning season with the time to maturation of oocytes shortened by as much as 3 months. Many of the captive males developed large, square-shaped heads with swollen cephalic epaxial muscles as spawning conditions approached, but their GSI values were not different from those of fish sampled at other times of the year. Injections of CPE increased the GSI value and vascularization of testes but not the number of spermatozoa. In general, sperm production in mature male madtoms was enigmatic in captive and wild fish, inasmuch as motile sperm were observed only once. The heads of margined madtom spermatozoa are slightly ovate (4.3 0.2 μm long and 3.6 0.2 μm wide). The tails are centrally attached to the head and are more than 112.5 μm long. A pronounced, collar-like midpiece encircles the posterior portion of the head and anterior portion of the tail. Plasma testosterone concentrations in males peaked just prior to the spawning season at 6.5 ng/mL, but levels were not correlated with male GSI values. Plasma 17β-estradiol levels in females peaked just prior to the spawning season at 15 ng/mL and were correlated with gonadosomatic values.

Reproductive strategy of the Pacific cownose ray Rhinoptera steindachneri in the southern Gulf of California

2019 ◽  
Vol 70 (1) ◽  
pp. 93 ◽  
Author(s):  
María I. Burgos-Vázquez ◽  
Valeria E. Chávez-García ◽  
Víctor H. Cruz-Escalona ◽  
Andrés F. Navia ◽  
Paola A. Mejía-Falla
Keyword(s):  
Gulf Of California ◽  
Size At Maturity ◽  
Annual Reproductive Cycle ◽  
La Paz ◽  
Cownose Ray ◽  
Large Size ◽  
Median Size ◽  
Disc Width ◽  
Gill Net ◽  
The Pacific

Rhinoptera steindachneri is one of the most common batoid species in the artisanal gill net fishery of the Gulf of California. In this study we investigated its reproductive biology based on 317 specimens caught in Bahía de la Paz, Mexico. Females measured up to 94.2-cm disc width (DW) and males reached 82.5cm DW; there were no significant differences in size or weight between sexes. The median size at maturity was estimated at 68.5cm DW for males and 71.8cm DW for females, and the median size at pregnancy was 84.3cm DW. Only the left ovary and uterus were functional; a maximum of six preovulatory vitellogenic follicles per female was recorded, although uterine fecundity was one embryo per female. Ovulation and birth occurred in May, June and July, with birth sizes ranging from 38.1 to 42cm DW. R. steindachneri in Bahía de la Paz exhibited low fecundity, large size at maturity and birth and a continuous and synchronous annual reproductive cycle.

scholarly journals Reproductive Ecology ofProchilodus brevisan Endemic Fish from the Semiarid Region of Brazil

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Liliane de Lima Gurgel ◽  
José Roberto Verani ◽  
Sathyabama Chellappa
Keyword(s):  
Gonadosomatic Index ◽  
Reproductive Ecology ◽  
Temporal Distribution ◽  
Gonadal Development ◽  
Neotropical Region ◽  
Reproductive Period ◽  
Semiarid Region ◽  
Spawning Period ◽  
Gonadal Maturity ◽  
Commercially Important

The commercially important migratory fishProchilodus brevisis from the Neotropical region, and understanding the reproductive ecology of this potamodromous fish is essential for its conservation and management. This study investigated the length-mass relationship, sex ratio, length at first gonadal maturity, gonadal development stages, gonadosomatic index, condition factor, and reproductive period ofP. brevis. Temporal distribution of rainfall, temperature, dissolved oxygen concentration, pH, and electrical conductivity of the water were related to the reproductive period of this fish. Rainfall seems to be the main environmental factor which modulates changes in limnological parameters and the timing of the spawning period of this fish.P. brevismigrates into lower reaches of the river to feed during the dry season and returns to the upper reaches during the rainy season to spawn. Inadequate facilities for migration create obstacles for spawning success of this ecologically important fish.

scholarly journals Mercado regional en el Golfo de California (1848-1910)

2016 ◽  
Vol 13 (22) ◽  
Author(s):  
Alfonso Guillén Vicente
Keyword(s):  
Gulf Of California ◽  
18Th Century ◽  
The South ◽  
La Paz ◽  
Regional Market ◽  
Industrial Sectors ◽  
The Pacific ◽  
Siglo Xix ◽  
Livestock Products ◽  
The 19Th Century

Resumen:El comercio marítimo que apareció en el Golfo de California a finales del siglo X V I I I, se afianzó en las primeras décadas del siglo XIX merced a la navegación de altura que tuvo como eje el puerto de San Blas, Nayarit, y al intercambio efectuado por las naves que cubrían los diversos destinos de la región con productos agrícolas y pecuarios. Su despegue definitivo, sin embargo, ocurrió con motivo de la fiebre del oro en California, que permitió el establecimiento de rutas regulares que tocaban los puertos de Guaymas, Mazatlán y La Paz . El propio desarrollo urbano de estas localidades constituyó un mercado interesante para los buques de vapor que se movían a lo largo del Pacífico. Los comerciantes locales se hicieron así de un respetable capital que invirtieron en otros sectores productivos de la región, además de fortalecer los lazos establecidos entre ellos. La entrada del ferrocarril a Sonora en la década de los ochenta del siglo XIX no eclipsó por completo a Guaymas, que por todo el resto de la centuria conservó un papel relevante como centro comercial regional. En la medida que el caballo de hierro abatió sus costos y se acreditó entre los sectores minero e industrial sonorenses y, sobretodo, cuando el Sudpacífico continuó su marcha hacia el Sur, al entrar en Sinaloa, el importante mercado regional del Golfo de California cayó de manera significativa.Palabras clave: comercio marítimo, navegación de altura, fiebre del oro en California , ferro carril, comercio en el Mar de Cortez.Abstract:Maritime trade that emerged in the Gulf of California in the late 18th century consolidated during the first decades of the 19th century thanks to deep-sea navigation, whose axis was the port of San Blas, Nayarit, as well as to trade carried out by the ships transporting agricultural and livestock products to the various destinations of the region. How ever, it took off once and for all owing to the gold fever in California, which allowed establishing regular routes that called at the ports of Guaymas, Mazatlán y La Paz. The urban development itself of these localities was a interesting market for the steamships sailing across the Pacific. Local merchants thus obtained a considerable capital which they invested in other productive sectors of the region, as well as strengthening the ties established among them. The arrival of the railroad in Sonora in the 1880s didn’t eclipse Guaymas completely, which played a important role as a regional business center for the rest of the century. As the Iron Horse reduced its costs and gained a good reputation among the Sonora mining and industrial sectors, and, above all, when the South Pacific carried on toward the south, arriving in Sinaloa, the important regional market of the Gulf of California fell significantly.Palabras clave: sea trade, ocean navigation, California gold fever, railroads, Cortez Sea trade.

scholarly journals PROLIFERATION OF Amphidinium carterae (GYMNODINIALES: GYMNODINIACEAE) IN BAHÍA DE LA PAZ, GULF OF CALIFORNIA

2012 ◽  
Vol 27 (2) ◽  
pp. 37 ◽  
Author(s):  
I. Gárate -Lizárraga
Keyword(s):  
Gulf Of California ◽  
New Records ◽  
Seawater Temperature ◽  
Prorocentrum Minimum ◽  
Benthic Species ◽  
La Paz ◽  
Amphidinium Carterae ◽  
The Pacific

During a sampling on 15 December 2011 in Bahía de La Paz, a bloom of the benthic dinoflagellate Amphidinium carterae was detected. Its abundance ranged from 28.2 to 64.8 × 103 cells L–1. Cells of A. carterae varied in length from 18 to 28 μm and 13 to 18 μm in wide (n = 30). The presence of A. carterae and benthic species of diatoms and dinoflagellates at the surface could be an indicator of upwelling water generated by northwestern winds. Seawater temperature during the bloom was 20 °C. Also, new records of dinoflagellates for the Mexican coast of the Pacific are here reported: Amphidiniopsis hirsuta, Amphidiniopsis sp., Amylax buxus, Cochlodinium pulchellum, Cochlodinium virescens, Durinskia cf. baltica, Gyrodinium sp., Thecadinium sp., and Prorocentrum minimum var. triangulatum. Proliferación de Amphidinium carterae (Dinophyceae: Gymnodiniales) en Bahía de La Paz, Golfo de California Durante un muestreo realizado el 15 de Diciembre de 2011 en Bahía de La Paz se detectó un florecimiento del dinoflagelado bentónico Amphidinium carterae. Los valores de abundancia variaron de 28.2 a 64.8 × 103 céls L–1. Los especímenes de A. carterae presentaron un intervalo de tallas de 18 a 28 μm de longitud y de 13 a 18 μm de ancho (n = 30). La presencia de A. carterae, así como de especies bentónicas de diatomeas y dinflagelados en superficie podrían indicar aguas de surgencia debido a la influencia de los vientos del noroeste en esta temporada. La temperatura del agua durante el florecimiento fue de 20 °C. También se reportan nuevos registros de dinoflagelados para la costa pacífica de México: Amphidiniopsis hirsuta, Amphidiniopsis sp., Amylax buxus, Cochlodinium pulchellum, Cochlodinium virescens, Durinskia cf. baltica, Gyrodinium sp., Thecadinium y Prorocentrum minimum var. triangulatum.

scholarly journals Reproductive period, fecundity and histology of gonads of two cheirodontines (Ostariophysi: Characidae) with different reproductive strategies - insemination and external fertilization

2010 ◽  
Vol 8 (2) ◽  
pp. 351-360 ◽  
Author(s):  
Cristina L. C Oliveira ◽  
Clarice B Fialho ◽  
Luiz R Malabarba
Keyword(s):  
Gonadosomatic Index ◽  
Relative Weight ◽  
Gonadal Development ◽  
Reproductive Period ◽  
Total Weight ◽  
Tropical Region ◽  
Temporal Separation ◽  
External Fertilization ◽  
Relative Fecundity ◽  
The Mean

The reproductive period and fecundity of the inseminating cheirodontine Compsura heterura and of the externally fertilizing cheirodontine Odontostilbe pequira, from tropical and subtropical regions of Brazil, respectively, are described. The reproductive period of C. heterura lasted from January to April 2002, while O. pequira showed two reproductive periods, the first during September and October 2001 (spring), and the second between January and February 2002 (summer). Smaller classes of SL of females of O. pequira predominated in the second reproductive period, suggesting individuals born in the first period become shortly sexually mature, participating in the second reproductive period. In C. heterura, from a tropical region, temperature showed significant correlations with the variation in the gonadosomatic index (GSI) for both sexes, and rainfall showed significant correlation with the variation in the GSI only for females. In O. pequira, from a subtropical region, photoperiod was the only factor that showed significant correlations with the GSI variation in both sexes. The mean relative fecundity of C. heterura was 0.55 oocytes per milligram of total weight, similar to that of other cheirodontines with external fertilization, refuting the hypothesis, at least in Cheirodontinae, that insemination provides diminishing energy expenditure for the production of oocytes, due to a greater probability of fertilization. The mean relative fecundity of O. pequira was 0.8 oocytes per milligram of total weight, the largest known among cheirodontines. Spermatozoa were found inside the ovaries of maturating, mature and semi-spent females of C. heterura supporting the hypothesis of temporal separation between courtship and spawning. The largest relative weight of testis and the presence of sperm in maturing ovaries outside the reproductive period in C. heterura support the hypothesis that males of inseminating species make a greater investment in gonadal development than those externally fertilized.

scholarly journals PROLIFERATION OF Levanderina fissa AND Polykrikos hartmannii (DINOPHYCEAE: GYMNODINIALES) IN BAHÍA DE LA PAZ, GULF OF CALIFORNIA, MÉXICO

2014 ◽  
Vol 29 (2) ◽  
pp. 25 ◽  
Author(s):  
I. Gárate -Lizárraga
Keyword(s):  
Gulf Of California ◽  
Phytoplankton Community ◽  
Red Tide ◽  
Symbiotic Association ◽  
La Paz ◽  
Phytoplankton Species Composition ◽  
The Pacific ◽  
Synechococcus Sp ◽  
Levanderina Fissa ◽  
First Time

On 19–20 August 2014, a moderate proliferation of dinoflagellates was detected in the southwestern part of Bahía de La Paz. The phytoplankton community within this red tide was composed of 60 microalgae taxa and was characterized by the presence of unarmored dinoflagellates such as Levanderina fissa and Polykrikos hartmannii. The proliferation occurred during low tide after a period of windy and rainy days. Densities of L. fissa varied from 163 to 265 × 103 cells L–1 and for P. hartmannii varied from 16 to 33 × 103 cells L–1. Low densities were estimated on September and October samplings. Both species showed a great variation both in size and form. As part of the phytoplankton species composition during this proliferation, two taxa of dinoflagellates are new records for the Pacific coast of Mexico (Ankistrodinium semilunatum and Sclerodinium calyptroglyphe), one in the Gulf of California (Pronoctiluca acuta), and one in the Bahía de La Paz (Prorocentrum robustum). Cyanobacteria were an important group observed during this proliferation. The symbiotic association between a cyanobacterium Synechococcus sp., the stramenopile protist Solenicola setigera, and the diatom Leptocylindrus mediterraneus was observed for the first time in this bay. Proliferación de Levanderina fissa y Polykrikos hartmannii (Dinophyceae: Gymnodiniales) en Bahía de La Paz, Golfo de California, México Se detectó una proliferación moderada de dinoflagelados en la porción suroeste de la Bahía de La Paz del 19 al 20 de agosto de 2014. La comunidad del fitoplancton dentro de este florecimiento estuvo compuesta de 60 taxa y se caracterizó por la dominancia de Levanderina fissa y Polykrikos hartmannii. La proliferación ocurrió durante la marea baja y después de días lluviosos. La abundancia de L. fissa varió de 163 a 265 × 103 céls L–1 y P. hartmannii varió de 16 a 33 × 103 céls L–1 . Densidades bajas fueron estimadas durante los muestreos de septiembre y octubre. Ambas especies mostraron una gran variación en su forma y su tamaño celular. Como resultado de la composición especifica del fitoplancton encontrado durante esta proliferación, dos taxa de dinoflagelados fueron nuevos registros para la costa Pacífica de México (Ankistrodinium semilunatum y Sclerodinium calyptroglyphe), un taxón para el Golfo de California (Pronoctiluca acuta) y un taxón para la Bahía de La Paz (Prorocentrum robustum). Las cianobacterias fueron un grupo importante durante esta proliferación. La asociación simbiótica entre una cianobacteria Synechococcus sp., el protista stramenopiles Solenicola setigera y la diatomea Leptocylindrus mediterraneus se observó por primera vez en la bahía.

scholarly journals Gonadal development and reproductive period of the characin Astyanax aff. bimaculatus (Characiformes: Characidae) in a tropical reservoir in southeastern Brazil

2019 ◽  
Vol 36 ◽  
pp. 1-14
Author(s):  
Francisco G. Araújo ◽  
Aparecida A. Nascimento ◽  
Iracema D. Gomes ◽  
Armando Sales ◽  
Beatriz A. Chagas de Oliveira
Keyword(s):  
Gonadosomatic Index ◽  
Gonadal Development ◽  
Neotropical Region ◽  
Reproductive Period ◽  
Southeastern Brazil ◽  
Energy Reserves ◽  
Tropical Reservoir ◽  
Spawning Period ◽  
Wide Range ◽  
Body Energy

The gonadal development of the characin Astyanax aff. bimaculatus from Funil Reservoir, an impoundment in the middle reaches of the Paraiba do Sul River in southeastern Brazil was analysed through histological, histochemical and histometric techniques, and the spawning season was determined. Unbalanced sex ratio was found, with females outnumbering and reaching larger sizes than males. The following stages of oogenic cell development were identified for females: primary growth, pre-vitellogenic (cortical alveolar) and vitellogenic. In males, the following stages were determined: spermatogonia primary and secondary, spermatocyte primary and secondary, spermatid and spermatozoa. The spawning occurs most of the year, peaking in January-February, as indicated by the gonadosomatic index. In the peak of the spawning period, the condition factor and hepatosomatic indices decreased suggesting use of stored body energy reserves during the reproduction. Spawning in batches, small-sized oocytes and a long reproductive season suggest that Astyanax aff. bimaculatus fits to an opportunist strategy. Such strategy may facilitate the use of a wide range of lentic and lotic body waters in the Neotropical region.

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